This invention relates broadly to furnaces, boilers, incinerators, and like equipment wherein fuel is burned.
More particularly, this invention relates to combustion equipment which regulates the flow of combustion air and fuel in response to a signal generated from a condition of a process.
Still more particularly, this invention relates to combustion equipment which will provide a fuel-lean mixture of combustion components as process conditions modify the demand for process heating.
The efficient control of combustion relates to the efficient control of the fuel and combustion oxidant, usually air. Efficient control of combustion is essential in the power industry, chemical industry, and various other process industries.
The amount of heat furnished by the combustion process depends upon the amount of heat needed by the operation requiring the heat, whether for the generation of power, or for the chemical process, or for an oil refinery process. In addition, the amount of heat needed will continually vary, thus requiring continual control of the combustion.
In some industries, particularly the power industry and the chemical industry, the relative efficiency of the combustion process may be accomplished by the use of elaborate control systems, such as computers, various kinds of automatic valves, and electronic controls.
As a result, numerous control systems have been designed to control the combustion processes. And, with time, these systems tend to become more elaborate. Then, as a system becomes more elaborate, the number of components, such as dials, gauges, recorders, computers, and the like, requiring the attention of the operatore, increases. With increased complexity, the probability of someone making a mistake increases greatly. The operator has an increased number of recording devices to observe and maintain, dials to continually observe, and switches to be ready to operate, for example.